connection: use close from superclass
connection: use close from superclass

We had our own re-implemented close function from when this was
first introduced which has since then drifted a lot from Ansible.

This drops all that code so that we can use the superclass when
closing the connection.

Change-Id: Id62e510af035988084453883278c3db85c8b7519

openstack/openstack-ansible-plugins,openstack/openstack-ansible-plugins